Pressure-gage.



M. L. OHILSON.

PRESSURE GAGE.

APPLICATION FILED 11011.25, 1911.

1,689,326 Patented Mar. 3, 1914.

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131 14 111240 $5 M 67 WM yam M. L. GHILSON.

PRESSURE GAGE.

APPLICATION FILED NOV. 25, 1911. 1 .fifig wfix Patsnted M3113, 191.4.

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lllilTTED STATES PATENT. OFFICE.

MARVIN LOGAN GHILSON, F WEBSTER, S OUTH DAKOTA.

PRESSURE-GAGE.

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Specification of Letters Patent.

Patented Mar. 3, 1914.

Application fil'ed November 25, 1911. Serial No. 662,461.

To all whom it may concern:

Be it known that I, MARVIN LOGAN CHIL- SON, a citizen of the UnitedStates, residing at \Vebsterg'in the county of Day and State of Soutl1'.Dakota, have invented new and useful Improvements in Pressure-Gages,of

which the following is a specification.

An object of the invention is to provide a gage for determining thepressure of fluids.

My invention embodies adevice more particularly adapted for use inconnection with pneumatic tires on automobiles and the like, fordetermining the pressure of the air in the tire.

To accomplishthe'desired result, use is made of a casing for connectionwith the reference denote corresponding partsjn all the views, and inwhich Figure 1 is a fragmentary side elevation of a wheel equipped witha pneumatic tire and showing my device applied thereto. Fig. 2 is avertical sectional view of my device showing the same in initial ornonregistering position. Fig. 3 is an enlarged vertical transversesectional view of the structure disclosed in F ig. 2, showing the gagein registering position.- Fig. 1 is a transverse sectional view taken onthe line 44- in Fig. 1., Fig. 5 is a transverse sectional view on theline 55 in Fig. 2. Fig. 6 is a perspective View of the piston and thehead thereof.

Referring to the views, I employ a vehicle wheel 10 provided with apneumatic tire 11 having the usual valve member 12 attached thereto forinflating the tire or exhausting' the air therefrom, the said valve lit)member consisting'of a casing 13 having a spring-actuated needle 1%mounted to slide therein, a valve 15 being mounted on the needle 14 tonormally close the opening of the casing and prevent the air in the tire11 from passing outwardly through the easing 13. i

The outer periphery of the casing 13 is preferably threaded and atubular casing 16 mounted in threaded engagement with the casing 13 asshown in Figs. 2 and 3, the Valve member 12 being mounted within thecasing 16 with the upper end of the needle l-il normally projecting adistance beyond the upper end of the casing 13.

A tubular casing 17 is provided with. an integral circular plate 18having an integral depending flange 19 and mounted to slide on thecasing 17 is a collar 20 provided with an integral upwardly extendingflange 21, a helical expansible spring 22 being mounted to encircle thecasing 17 with the upper end of the spring abutting against the plate 18and the lower end of the spring abutting against the collar 20, theflanges 19 and 21 being provided to act as guards for the spring 22 toproperly retain the ends of the spring in engagement with the plate 18and collar 20. A portion of theperiphcry of the collar 20 is threadedfor engagement with the upper end of the casing 16 and suitable stoppins 23 are secured to the casing 17 to limit the upward slidingmovement of the casing 17 in the collar 20. The periphery of the casing17, at the upper end thereof, is'threaded to receive a tubular cap 24and mounted to slide in the casing 17 is a piston 25, provided at thelower end thereof with. a piston head 26, the mentioned piston, beingadapted to project upwardly; through the tubular port-ion of the cap 2%,a knob 27 being provided on the upper end of the piston 25, 'exteriorlyof the cap 24. The casing 17 is made substantially air-tight by havingthe piston 25 of a sufficient diameter to snugly pass through theopening in the cap 24: so that only a small amount of air, if any, canescape from the casing 17. The piston 25 is provided with a series ofgraduations 2S and mounted within the casing 17, to encircle the piston25 is an expansible helical spring 29, the said spring being mounted sothat the upper end thereof will abut against the under secured to theunder side of the bottom of the casing 17 and provided with an opening34, adapted to register with the opening 80 the said washer beingadapted to provide an air-tight joint between the casing 17 and theupper end of the valve casing when the valve is in open position.

N ow assuming that my device is attached to the casing 13 of the valvemember 12, as shown in Fig l and that the various parts of my device arein initial position as shown in Fig. 2, when it is desired to determinethe air pressure in the tire 11, a downward pressure is exerted on theplate 18 by the operator, thus moving the entire casing 17 downwardly sothat the needle seat 32 will engage the upper end of the needle 14- tomove the same downwardly, thus unseating the valve 15 from the casing 13so that the air contained in the tire 11 will pass outwardly through theopening in the casing 13. Now as the air passes outwardly from thecasing 13, it will pass upwardly through the opening 30 and strike theunder side of the piston head :26, thus moving the piston" 25 and pistonhead 26 upwardly, in the ing 17, against the action of the spring 29 sothat the pressure of the air can be determined by reading the particulargraduation 28 or fractional gra duation'thereof that registers with theupper surface of the cap 24. By releasing the downward pressure on theplate 15, the spring 22 will move the casing 17 back to its normalposition, thus causing the needle to move upwardly and the valve 15 willthen close the opening in the easing 13.

Although I have described my device as employed in connection witha,pneumatic tire, it will be readily seen that the gage can beconveniently employed for determining the pressures of various fluidsand it will be understood that I do not limit myself to the particularmanner of connecting the casing 17 to the casing 16 or the casing 16 tothe casing 13, the scope'of the invention being defined in the appendedclaims.

I claim I p p 1. In a pressure gage, the combination with a casing i'orconnection wlth a valve member, of a second casing having slidableconnection with the first casing and movable longitudinally therein,means for normally holding the second casing in extended position in thefirst casing, and apressure regi$- tering device mounted to slide in thesecond casing, the said second casing being movable in the firstmentioned casing to engage and release the valve of the said valvemember.

2. In a pressure gage, the combination with a casing for connection witha valve member, of a second casing having slidable connection with thefirst casing and movable longitudinally therein, a spring for normallyholding the second casing in extended position in the first casing, anda spring-engaged graduated pressure registering device slidably mountedin the second casing, the said second casing being movable in the firstmentioned casing and against the action of the first mentioned spring toengage and release the valve of the valve member.

3. In a pressure gage, the combination with a casing for connection witha valve member, of a second casing having slidable connection with thefirst casing and movable longitudinally therein, a spring for normallyholding the second casing in extended position in the first casing, acap for the second casing, a pressure registering piston mounted in thesecond casing and slidably extending through the said cap, and a springengaging the said cap and thesaid piston to normally retain the pistonin lowermost positio-n within the second casing, the said sec- 0ndcasing being movable in the first casin r to engage and release thevalve of the said valve member.

4. The combination of two members tele- "scoped to form a pressurereceiving chamber, one member being adapted for screw connection with atire valve casing, a spring normally holding the members in extendedrelation, the second member carrying means to engage and open the tirevalve when said member is depressed against the action of the spring,and means also carried by said second member and responsive to thepressure of air admitted to the chamber for indicating the amount ofsuch pressure.

In testimony whereof I aflix my signature in presenceof two witnesses.

MARVIN L GAN CHILSON. Vitnesses lVaRD PIERCE,

ALBERT SMITH.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G."

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